Gripped by mid-life crisis a 46 year old teacher decides to try an adventure holiday and learns the importance of life on the bloodied streets of Kathmandu.

Note

On a side not; love "The man who knew too little"

I agree that the conflict needs to be clearer... Also because you've mentioned that it's a mid-life crisis there is no need to specify age. Instead a description of the teacher (inhibited, shy, spirited, British, Hungarian...) would help us understand what kind of a person he/she is.

Gripped by a mid-life crisis, an inhibited British teacher signs up for an adventure holiday, but gets a lesson in life, when a ("antogonist") pulls her into (whatever they're up to) on the bloodied streets of Kathmandu

Obviously, still needs a lot of work.
What genre are you aiming for? Using the language of the genre is an important aspect of a solid logline. Right now it reminds me of "The Man Who Knew Too Little" - with Bill Murray. Not a bad thing at all.